The conventional folder is generally made of paper or plastic boards. The disadvantages are as follows:
1. As the folder requires binding and bearing of documents internally, thin paperboard will make the folder too soft to bear the weight of documents or withstand the external force. If the thickness of paperboard is increased, the paper folder will become uneconomical owing to a higher cost of paper as compared to plastics. Even if its ruggedness is improved by increasing the thickness of paperboard, the paper folder will be softened as it is impossible to block off the humid air or water.
2. In an effort to reduce the cost and improve the quality of paper folder, the present invention has created a folder by plastic board. However, this soft folder is unable to bear the weight of documents in the presence of thin plastic board. Additionally, the plastic board is made of monochromatic molding materials, which cannot bring chromatism and diversity for the folder.
3. Either conventional paper folders or plastic folders are unavailable with lightweight advantage. If there are many files in the cumbersome folder, the end-user must hold it in the palm or carry it by both hands, more particularly to female users. Thus, conventional folders are really hard-to-carry.
Based upon years of experience in R&D and design of this product, the present invention has offered a utility model after detailed evaluation and careful design.